Jamming-resistant wireless transmission of security data

ABSTRACT

A jamming-resistant method and system transmit security data through a wireless telecommunication network from a first station to a second station remote from the first station. Prior to transmission, common access channels of the wireless telecommunication network are determined. The security data are then transmitted from the first station to the second station through a plurality of the common access channels of the wireless telecommunication network. The security data may be transmitted from the first station to the second station without receiving local access parameters from the wireless telecommunication network at the time of transmission.

FIELD OF THE INVENTION

[0001] The present invention relates to jamming-resistant method andsystem for transmitting through a wireless telecommunication networksecurity data from a first station to a second station remote from thefirst station.

BACKGROUND OF THE INVENTION

[0002] Tracking Systems:

[0003] Tracking systems are designed and implemented to enable people toremotely determine the position or location of their assets. Trackingsystems are widely used in many logistic applications such as fleetmanagement, and in many security applications such as stolen assetrecovery.

[0004] Tracking systems comprise a mobile station and usuallyincorporate two technologies:

[0005] 1. A positioning/navigation technology such as GPS (GlobalPositioning System), cellular triangulation, or dead reckoning todetermine the coordinates of the mobile station being tracked; and

[0006] 2. A wireless telecommunication technology such as cellular orsatellite communication to transmit the coordinates or reference signalfrom the mobile station to a remote, mobile and/or stationary station.

[0007] The wireless technology must work for the tracking system tooperate properly.

[0008] For the application to tracking systems, the commercial wirelesstelecommunication networks present the drawback of being vulnerable tojammers, which can interfere with or prevent clear reception ofair-borne EMW (Electro-Magnetic Wave) signals. For instance, thefollowing Table 1 compares the commercial jammers (transmitters in thereceiving band of the mobile station) and military jammers. TABLE 1Jammers Commercial Military Intended appiication is to create a Intendedapplication is warfare. cellular service hole in theatres, restaurants,and places of worship to eliminate cellular ring tones and phoneconversations. Operation constrained by regulation. No regulationapplies. Widely distributed and large Very limited legal market, andinternational market. Illegal in Canada distribution controlled byspecial and the U.S., yet easily available: one government agencies. canorder a jammer over the Internet and receive the unit 48 hours later.Low-power radiation blocks all High-power radiation blocks thecommercial downlink bands by receivers of all neighboring basegenerating noise near terminal receiver. stations, effectively puttingUsage affects subscribers in room (for several thousand subscribers outexample 10-100 meter radius area) or of service. This is a major civilonly immediate vicinity of truck/cargo. disturbance that would mobilizepublic emergency services. The high power radiation makes the sourceeasy to locate quickly so this jammer would not be an obvious choice tosupport a theft. Undetectable by network operator. Network alarms aretriggered and emergency procedures could take effect to re-establishservice and identify source of problem.

[0009] Therefore, individuals can today disable any commercial trackingsystem using a jammer purchased online through the Internet for a fewhundred dollars. This is of major concern to those who use trackingsystems for security purposes such as fleet owners, insurance companies,and governments keeping a close watch on the transport of hazardousmaterials.

[0010] Alarm Systems:

[0011] In the case of alarm systems, status and identificationinformation must be communicated to remote monitoring stations.Normally:

[0012] 1. Mobile alarm systems use wireless telecommunications; and

[0013] 2. Fixed alarm systems today use wireline telecommunications as afirst resource. High-end systems offer a wireless telecommunicationservice as backup in case wireline communications fail.

[0014] Again, the wireless telecommunication link used in alarm systemscan be disabled by means of a jammer purchased online through theInternet for a few hundred dollars.

SUMMARY OF THE INVENTION

[0015] According to the invention, there is provided a jamming-resistantmethod for transmitting security data through a wirelesstelecommunication network from a first station to a second stationremote from the first station, comprising: determining, prior totransmission, common access channels of the wireless telecommunicationnetwork; and transmitting the security data from the first station tothe second station through a plurality of these common access channelsof the wireless telecommunication network.

[0016] The present invention also relates to a jamming-resistant systemfor transmitting security data through a wireless telecommunicationnetwork from a first station to a second station remote from this firststation. The wireless telecommunication network comprises common accesschannels, and the jamming-resistant system comprises a transmitter ofthe security data from the first station to the second station through aplurality of the common access channels of the wirelesstelecommunication network.

[0017] The foregoing and other objects, advantages and features of thepresent invention will become more apparent upon reading of thefollowing non restrictive description of illustrative embodimentsthereof, given for the purpose of illustration only with reference tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the appended drawings:

[0019]FIG. 1 is a schematic diagram illustrating the structure of anautonomous registration frame sent by a mobile station over an accesschannel of a wireless telecommunication network;

[0020]FIG. 2 is a flow chart showing the operation of ajamming-resistant wireless transmission method according to a firstillustrative embodiment of the present invention;

[0021]FIG. 3 is a block diagram of a first version of wireless mobilestation according to the first illustrative embodiment of the presentinvention;

[0022]FIG. 4 is a block diagram of a second version of wireless mobilestation according to the first illustrative embodiment of the presentinvention; and

[0023]FIG. 5 is a flow chart showing the operation of ajamming-resistant wireless transmission method according to a secondillustrative embodiment of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0024] Illustrative embodiments of the present invention will now bedescribed with reference to the accompanying drawings.

[0025] All communication protocols used in wide area wirelesstelecommunication networks require the mobile stations to receive atleast one of the following local access parameters from the wirelesstelecommunication network before transmitting:

[0026] the frequency channel on which the mobile station shouldtransmit;

[0027] the time slot during which the mobile station should transmit;

[0028] the code which should be used to spread, scramble or discriminatethe narrowband signal;

[0029] the transmission power; and

[0030] the synchronisation frame.

[0031] Commercial jammers disable the receivers of all mobile stationswithin a variable radius typically in the range of 10-100 meters. Morespecifically, since the mobile stations no longer receive the abovelisted local access parameters in the presence of a jammer, the mobilestations do not transmit.

[0032] Therefore, a jammer will prevent a mobile station from receivinginformation from a wireless telecommunication network. However,commercial jammers do not prevent the mobile stations from transmittingdata to the same network. Accordingly, it is possible for a mobilestation to transmit data to a wireless telecommunication network usingcurrent frequency plans and multiple access schemes. The transmitteddata could comprise security data such as identification, alarm,position and/or displacement information, and/or any other useful data.

[0033] Cellemetry Virtual Network:

[0034] In the first illustrative embodiment, as depicted in FIGS. 1, 2,3 and 4, the mobile station 301 (FIG. 3) transmits information to aCellemetry virtual network.

[0035] In the following description of the first and second illustrativeembodiments of the present invention, the time period before asecurity-breach “event” is referred to as the “pre-event” period. In thesame manner, the time period after the security-breach “event” isreferred to herein as the “post-event” period.

[0036] During the post-event period, the mobile station 301 (FIG. 3) isassumed to remain within the coverage of the wireless telecommunicationnetwork detected by the mobile station 301 just before the event.

[0037] The jamming-resistant cellular uplink of the first illustrativeembodiment is based on piggybacking data on the autonomous registrationframe shown in FIG. 1. The idea behind this first illustrativeembodiment of FIGS. 1, 2, 3 and 4 is to replace the ESN (Electric SerialNumber) with 32 bits of data, to send the autonomous registration frameon all possible common access channels of the Cellemetry virtual networkand, then, to route the autonomous registration frame to a remotestation.

[0038] As a non-limitative example, FIG. 1 shows a TIA-553 (AMPS(Advanced Mobile Phone Service)) autonomous registration frame sent bythe mobile station 301 over the RECC (Reverse Control Channel) of acommon access channel to a wireless cellular telecommunication network.The autonomous registration frame comprises a serial bit streamincluding a 30-bit dotting, an 11-bit word sync, a 7-bit coded DCC(Digital Colour Code), WORD A, WORD B, and WORD C. WORD A is repeatedfive (5) times within a first stream of 240 bits, WORD B is repeatedfive (5) times within a second stream of 240 bits, and WORD C isrepeated five (5) times within a third stream of 240 bits.

[0039]FIG. 1 further describes the constitution of the 30-bit dotting,11-bit word sync, 7-bit coded DCC, WORD A, WORD B, and WORD C. Asillustrated in FIG. 1:

[0040] the 30-bit dotting is a repetitive stream of bits such as“101010101010101010101010101010”;

[0041] the 11-bit word sync is a stream of bits such as “11100010010”;

[0042] the 7-bit coded DCC is

[0043] 0000000 (for channel 00)

[0044] 0011111 (for channel 01)

[0045] 1100011 (for channel 10)

[0046] 1111100 (for channel 11)

[0047] WORD A is an abbreviated address word having a structure such asthe one illustrated in FIG. 1, comprising a first MIN1 (MobileIdentification Number);

[0048] WORD B is an extended address word having a structure such as theone illustrated in FIG. 1, comprising a second MIN2 (MobileIdentification Number); and

[0049] WORD C is the third word of the called address having a structuresuch as the one illustrated in FIG. 1, comprising a 32-bit serial ESN101 which is replaced, as indicated in the foregoing description, with32 bits of data.

[0050] These 30-bit dotting, 11-bit word sync, 7-bit coded DCC, WORD A,WORD B, and WORD C are otherwise well known to those of ordinary skillin the art and, accordingly, will not be further described in thepresent specification. In particular, these 30-bit dotting, 11-bit wordsync, 7-bit coded DCC, WORD A, WORD B, and WORD C are fully described inthe following AMPS specifications: Mobile Station—Land StationCompatibility Specification EIA/TIA-553, September 1989, incorporatedherein by reference.

[0051] Referring now to FIG. 3, the mobile station, generally identifiedby the reference 301, comprises an AMPS parameters monitor 302, ajammer/alarm detector 303, a store 304 for the last updated key AMPSparameters, a processor 305 for determining the common access channels,and a security data transmitter 306.

[0052] Step 201 (FIG. 2):

[0053] Referring to FIG. 2, in the pre-event period (step 201), themobile station 301 (FIG. 3) is in the idle AMPS mode. In this particularmode, during the pre-event period, the mobile station 301 acts as astandard Cellemetry terminal; the AMPS parameters monitor 302 of themobile station 301 monitors, updates and keeps in memory the followingkey AMPS parameters or variables received from the wireless cellulartelecommunication network (substep 201 ₂) through overhead systemmessages (substep 201 ₁) transmitted from the wireless cellulartelecommunication network through dedicated control or paging channels,for example FOCCs (Forward Control Channels):

[0054] N: Number of paging channels;

[0055] CPA: Combined paging/access field;

[0056] CMAX: Number of access channels;

[0057] NEWACC: New Access Channel; and

[0058] DCC: Digital Colour Code (useful for fixed application of themobile station).

[0059] Step 202:

[0060] In step 202, a jammer/alarm detector 303 detects the presence ofa jammer or alarm (security breach). If no jammer or alarm is detected,the process returns to step 201.

[0061] For example, a jammer is detected when a loss of contact betweenthe mobile station and the telecommunication network is detected.

[0062] Step 203:

[0063] In response to detection of a jammer (proximate the mobilestation 301) or an alarm by the detector 303, i.e. once an event isdetected the AMPS parameters monitor 302 stops updating the values ofthe above mentioned key AMPS parameters based on the overhead systemmessages (substep 201 ₁) received from FOCCs of the cellular network.The last updated key AMPS parameters are then stored into a store 304.

[0064] Step 204:

[0065] The purpose of the Cellemetry's modifications to the TIA-553(AMPS) autonomous registration frame were to create an uplink datachannel through the autonomous registration procedure. Morespecifically, the modifications are:

[0066] 1. Replacing the ESN (Electric Serial Number) 101 of WORD C(FIG. 1) of the autonomous registration frame with 32 bits of data; and

[0067] 2. Forcing the autonomous registration to occur when the mobilestation 301 (application software) has data to send.

[0068] In step 204, the first (FIRSTCHA) and last (LASTCHA) accesschannels are determined by a processor 305 (FIG. 3) using the followingstandard equations:

[0069] If mobile station 301 stands on an A-band system (B-band caseuses a similar procedure):

[0070] if paging and access channels are combined (CPA=1), set FIRSTCHAto the first dedicated control channel on A-band System:

[0071] 834.990 MHz mobile Tx, 879.990 MHz land Tx and the last accesschannel (LASTCHA) to:

LASTCHA=FIRSTCH−CMAX+1

[0072] if paging and access channels are not combined (CPA=0), setFIRSTCHA to the first dedicated control channel on A-band system minusN× channel bandwidth:

(834.990−N×0.030) MHz mobile Tx, (879.990−N×0.030) MHz land Tx

[0073] and the last access channel (LASTCHA) to:

LASTCHA=FIRSTCH+CMAX−1

[0074] if NEWACC specified, set

FIRSTCHA=NEWACC

LASTCHA=NEWACC−CMAX +1

[0075] Step 205:

[0076] The mobile station 301 then proceeds with sending security datain 32-bits messages through a transmitter 306 (FIG. 3) to the desireddestination, for example a remote station (not shown) of anevent-monitoring service.

[0077] Step 206:

[0078] As indicated in the foregoing description the ESN 101 of WORD Cof the autonomous registration frame is replaced by the security data tobe transmitted to the remote station.

[0079] Then, when used in a mobile application (for instancetelematics), the transmitter 306 of the mobile station 301 transmits theautonomous registration frame [(LASTCHA−FIRSTCHA+1)×4] times, i.e. onceon each possible RECC access channel within the range between the firstaccess channel FIRSTCHA and the last access channel LASTCHA, with allfour (4) DCCs (substep 206 ₁).

[0080] If used in a fixed application (for instance home alarms), thetransmitter 306 of the mobile station 301 transmits the autonomousregistration frame on one or more RECC access channels withcorresponding DCC (substep 206 ₁). Since the mobile station is notmoving, it should always remain in the coverage of the same neighbouringbase station(s).

[0081] Modifications to the first illustrative embodiment can be done toincrease the rate in which information can be successfully transmittedin a jamming resistant fashion. In fact, three different modificationsapplicable to the first illustrative embodiment have been identified:

[0082] MIN rotation;

[0083] Multi-carriers transmission;

[0084] MIN information encoding

[0085] MIN Rotation:

[0086] Basic Cellemetry uses a single MIN (Mobile Identification Number)to make the registration request. In the first illustrative embodimentof the present invention, the MIN of the autonomous registration frameis formed by MIN1 of WORD A and MIN2 of WORD B (FIG. 1) and identifiesthe remote station of the event monitoring service to which the securitydata has to be transmitted. The MIN and ESN are forwarded to theCellemetry server on an inter-cellular network (for example an IS-41inter-cellular network), where the encapsulated 32 bits of data arereceived. Since the ESN has been replaced by the security data (32 bitsof data), the ESN is not recognized by the Cellemetry server, and a“reject registration request” message is sent back to the host network.The host network then deletes the record from the VLR (Visitor LocationRegister). This loop can take as much as 1 minute to complete, and theterminal with the same MIN is unable to send an additional registrationrequest. This system would offer a 32 bits/minute bandwidth.

[0087] To increase the bandwidth, one can use MIN rotation. For example,one can assign a large number of slave MINs to every mobile station inaddition to the MIN used to uniquely identify the mobile station. Afterthe first registration request is sent over a plurality of common accesschannels using the uniquely identifying MIN of the mobile station,subsequent registration requests carrying new 32-bits serial ESNs aresent over a plurality of common access channels using different MINs.The throughput of 32 bits per minute initially achieved will then beincreased by the number of autonomous registration requests successfullyreceived using a different MIN and a new ESN. For example, assuming themobile transmits one third (⅓) of the time, RECC transmission lasts onetenth of a second, and 84 access channels/codes combinations exist,approximately 7 unique RECC transmissions will be received for athroughput of 224 bits/minute. The minimum number of slave MINs requiredto implement this case would be 6.

[0088] Multi-Carriers Transmission

[0089] Consider a cellular network with j access channels/codecombinations. In order to ensure reception by the network of theautonomous registration request under jamming conditions, it isnecessary to transmit sequentially in time j copies of the autonomousregistration request, once over each access channel/code combinations.

[0090] In order to increase the bandwidth of the jamming-resistant datauplink by a factor M, multi-carriers transmission can be used to enablethe mobile station to radiate on M access channels simultaneously. FIG.4 illustrates the first illustrative embodiment with the multi-carrierstransmission modification.

[0091] As illustrated in FIG. 4, the mobile station comprises aprocessor 401 for generating a bit stream for transmission to the remotestation. This bit stream is transmitted through a first modulators 402 ₁operating at the frequency of a first access channel carrier, a secondmodulators 402 ₂ operating at the frequency of a second access channelcarrier, . . . a M^(e) modulators 402 _(M) operating at the frequency ofa M^(e) access channel carrier. The modulated outputs from themodulators 402 ₁, 402 ₂, . . . 402 _(M) are processed through an adder403 prior to being radiated toward the base station(s) of the AMPSnetwork.

[0092] MIN Information Encoding

[0093] The selection of a given slave MIN can also be used to sendinformation and to increase the throughput. If 2^(N) slave MINs weretemporary assigned to a mobile station, an information block of N bitscan be encoded to one of the 2^(N) slave MINs. For example, assumingN=10, the use of this encoding scheme can increase the throughput by31%, as 10 information bits can be appended to the 32 bits alreadytransmitted using the ESN on a given registration message.

[0094] Since the MIN identifies the remote station of the eventmonitoring service to which the security data has to be transmitted, theMIN is used by the Cellemetry server to return the ESN to this remotestation of the event monitoring service (substep 206 ₃).

[0095] The remote station of the event monitoring service finallyprocesses the received security data (substep 206 ₄).

[0096] Step 207:

[0097] When all data have been sent, the transmission process isterminated. As long as there are data left to sent, transmitter 306keeps transmitting data to the remote destination station.

[0098] GSM (Global System for Mobile Communications) Network:

[0099] In the second illustrative embodiment, as depicted in FIG. 5, themobile station transmits information to a GSM wireless cellulartelecommunication network.

[0100] More specifically, the transmission relies on the use of theGSM's RACH (Random Access Channel) to transmit security data, while asecurity GSM based mobile station is being jammed by a commercialjammer. The RACH is the only uplink channel in GSM that does not requiretiming advance information. The timing advance is an estimation of thepropagation delay between a mobile station and its serving base station.The timing advance is calculated and sent by the base station.

[0101] The RACH is normally used to request an immediate assignment toinitiate a call or during a handoff. The RACH is sent during an accessburst, which contains a long guard band (equivalent 68,25 bits) whichmakes it immune to varying propagation delay.

[0102] Some modifications must be made by the operator to enableimplementation of the second illustrative embodiment of the presentinvention. The following summarizes the principal changes:

[0103] a) The operator must synchronise its base stations (GPS network)together so that all time slots TS0 are sent at the same time. Thisrequirement must already be implemented for an operator who wants tosupport EDGE (Enhanced Data rates for Global Evolution) compact, whichwas standardised in GSM Release 99.

[0104] b) The operator must use a regular frequency pattern, (i.e. 4/12(clusters of 4 cells /12 sectors) or 3/9 (clusters of 3 cells /9sectors) in order to use the new concept of fundamental frequencycarriers. In the case of frequency pattern 4/12, 12 fundamentalfrequencies (one per sector) are defined by the GSM network so that ajammed mobile station knows “a priori” on which frequencies should thedevice send its RACH. Time slot TS0 of a fundamental frequency must bereserved for Common Control Channels. Time slot TS1 can be used forvoice traffic or in priority for traffic of security data from one ormore mobile stations being jammed. Many operators use this type offrequency allocation, where the Time Slot TS0 of the first 12 frequencycarriers of its spectrum allocation are used for transmitting the BCCH(Broadcast Control Channel) on the downlink and RACH on the uplink.

[0105] c) The GSM network must be modified to correctly process thesequence 01100xxx sent over the RACH on the time slot TS0 of thefundamental frequencies, to enable access to the GSM network.

[0106] d) The GSM network must be modified to correctly group and routethe security data.

[0107] Referring to the flow chart of FIG. 5, the operation of thesecond illustrative embodiment of the present invention will bedescribed.

[0108] Step 501:

[0109] The mobile station is in the idle GSM mode until a jammer or anyother alarm (security breach) is not detected by step 502.

[0110] Step 502:

[0111] When the presence of a jammer (proximate the mobile station) orany other alarm is detected, the mobile station goes to step 503.Otherwise, the mobile station remains in the idle GSM mode (step 501).

[0112] Step 503:

[0113] In response to detection of a jammer or alarm, a random number ofthree (3) bits is selected. This random number forms the last three (3)bits of the RACH for local identification, i.e. identification of themobile station. More specifically, as indicated in substep 503 ₁, a bitstream including a reserved RACH sequence 01100xxx (ref. GSM04.08 R97)is generated and transmitted over the time slot TS0 of the fundamentalcarriers of the GSM system, where the term xxx represents the randomnumber identifying the mobile station.

[0114] As indicated in the above modification b), time slot TS0 of afundamental frequency is reserved for Common Control Channels. Time slotTS1 can be used for voice traffic or in priority for traffic of securitydata from one or more mobile stations being jammed or detecting analarm. Many operators use this type of frequency allocation, where thetime slot TS0 of the first 12 frequency carriers of its spectrumallocation are used for transmitting the BCCH.

[0115] The mobile station being jammed or detecting an alarm thereforeregisters in the GSM network through the time slot TS0 of thefundamental carriers. The GSM network then recognizes the reserved RACHsequence 01100xxx, to reserve or liberate the time slot TS1 of thefundamental carriers. The mobile station then proceeds with generating abit stream suitable for transmitting the security data from the mobilestation to the remote station of an event-monitoring service (substep503 ₂) through the time slot TS1.

[0116] Step 504:

[0117] Following transmission of the reserved RACH sequence to the GSMnetwork, a waiting period is provided for to allow the network to freeup the time slot TS1. This waiting period can be of the order of 100 ms.

[0118] Step 505:

[0119] Then, the security data are sent in five (5) bits messages. Thistransmission of the security data comprises step 506, and substeps 506₁, 506 ₂ and 506 ₃.

[0120] Step 506:

[0121] The security data are sent on the first five (5) bits of RACH.The last three (3) bits are for local identification of the mobilestation. More specifically, as indicated in subset 506 ₁, the time slotTS1 of the fundamental carriers of RACH is used for transmittingsequences pppppxxx, in which the term ppppp is the security data and xxxis used for discrimination; more specifically the term xxx willrepresent the above mentioned random number identifying the mobilestation. Thereafter, the GSM network routes the security data associatedwith the local identification information xxx to the remote station(substep 506 ₂). The identification number of the remote station will beprovided by the term ppppp of the first sequences pppppxxx. The securitydata are processed (substep 506 ₃) as soon as they reach the remotestation of the event-monitoring service.

[0122] Step 507:

[0123] The security data are processed until no data are left to send.

[0124] The above described illustrative embodiments of the presentinvention can be implemented for a plurality of different applicationssuch as, for example:

[0125] Jamming-resistant alarm notification;

[0126] Jamming-resistant GPS tracking;

[0127] Jamming-resistant real-time vehicle tracking; and

[0128] Jamming-resistant real-time cargo tracking.

[0129] Also, the above described first and second illustrativeembodiments can be used in connection with both cellular and satellitewireless telecommunication systems.

[0130] Although the illustrative embodiments of the present inventionhave been described in relation to AMPS and GSM wireless cellulartelecommunication networks, it should be kept in mind that the presentinvention can be equally applied to other cellular telecommunicationsstandard such as CDMA.

[0131] Although the present invention has been described hereinabovewith reference to illustrative embodiments thereof, it should be kept inmind that these illustrative embodiments can be modified at will, withinthe scope of the appended claims, without departing from the spirit andnature of the invention.

What is claimed is:
 1. A jamming-resistant method for transmitting security data through a wireless telecommunication network from a first station to a second station remote from said first station, comprising: determining, prior to transmission, common access channels of the wireless telecommunication network; and transmitting the security data from the first station to the second station through a plurality of said common access channels of the wireless telecommunication network.
 2. A jamming-resistant method as defined in claim 1, wherein the security data are transmitted from the first station to the second station without receiving local access parameters from the wireless telecommunication network at the time of transmission.
 3. A jamming-resistant method as defined in claim 1, comprising: detecting a security-breach event; and transmitting the security data from the first station to the second station through the plurality of common access channels in response to detection of the security-breach event.
 4. A jamming-resistant method as defined in claim 1, comprising: detecting the presence of a jammer proximate the first station, said jammer producing an emission interfering with transmission from the wireless telecommunication network to prevent said transmission from the network to reach the first station; and transmitting the security data from the first station to the second station through the plurality of common access channels in response to detection of the presence of a jammer.
 5. A jamming-resistant method as defined in claim 1, wherein transmitting the security data comprises sending from the first station an autonomous registration frame to the plurality of common access channels of the wireless telecommunication network.
 6. A jamming-resistant method as defined in claim 3, wherein the wireless telecommunication network is an AMPS network, and wherein the jamming-resistant method further comprises: prior to detection of a security-breach event: receiving AMPS parameters from the wireless telecommunication network; updating the received AMPS parameters; and keeping in memory the updated AMPS parameters; and after detection of a security breach event: storing the last updated AMPS parameters; and sending an autonomous registration frame to the wireless telecommunication network through the plurality of common access channels of the network selected in relation to the last updated AMPS parameters.
 7. A jamming-resistant method as defined in claim 6, further comprising: determining, in relation to the last updated AMPS parameters, a first common access channel and a last common access channel defining a range of access channels including said plurality of common access channels.
 8. A jamming-resistant method as defined in claim 5, wherein transmitting the security data from the first station to the second station comprises inserting the security data in the autonomous registration frame and transmitting said autonomous registration frame to the second station through the wireless telecommunication network.
 9. A jamming-resistant method as defined in claim 8, wherein the autonomous registration frame comprises a mobile identification number, and transmitting the security data through the plurality of common access channels comprises transmitting successive sets of security data respectively inserted in successive autonomous registration frames through the plurality of common access channels using a rotation of a plurality of mobile identification numbers in the successive autonomous registration frames.
 10. A jamming-resistant method as defined in claim 1, wherein transmitting the security data through the plurality of common access channels comprises using a plurality of access channel carriers for transmitting said security data through the plurality of common access channels, respectively.
 11. A jamming-resistant method as defined in claim 8, wherein transmitting the security data through the plurality of common access channels comprises: assigning at least one slave mobile identification number to the first station; encoding information by means of said at least one slave mobile identification number; and inserting said at least one encoded, slave mobile identification number in the autonomous registration frame.
 12. A jamming-resistant method as defined in claim 8, comprising: inserting in the autonomous registration frame a station identification number corresponding to the second station, and transmitting the autonomous registration frame to the second station through the wireless telecommunication network in response to the station identification number.
 13. A jamming-resistant method as defined in claim 12, wherein transmitting the autonomous registration frame to the second station comprises transmitting the autonomous registration frame to the second station through a Cellemetry virtual network.
 14. A jamming-resistant method as defined in claim 1, wherein transmitting the security data through the plurality of common access channels comprises sending from the first station a random access channel sequence to the wireless telecommunication network.
 15. A jamming-resistant method as defined in claim 14, wherein the wireless telecommunication network uses a plurality of fundamental frequency carriers each having first and second time slots, and wherein sending the random access channel sequence comprises sending the random access channel sequence through the first time slot of the fundamental frequency carriers.
 16. A jamming-resistant method as defined in claim 15, further comprising inserting in the random access channel sequence a random number identifying the first station.
 17. A jamming-resistant method as defined in claim 15, further comprising: liberating the second time slot of the fundamental frequency carriers of the wireless telecommunication network in response to reception of the random access channel sequence; and transmitting from the first station to the second station a second sequence including the security data through the second time slot of the fundamental frequency carriers.
 18. A jamming-resistant method as defined in claim 17, further comprising inserting in the second sequence a random number identifying the first station.
 19. A jamming-resistant system for transmitting security data through a wireless telecommunication network from a first station to a second station remote from said first station, wherein the wireless telecommunication network comprises common access channels, and wherein the jamming-resistant system comprises: a transmitter of the security data from the first station to the second station through a plurality of said common access channels of the wireless telecommunication network.
 20. A jamming-resistant system as defined in claim 19, wherein the transmitter comprises means for transmitting the security data from the first station to the second station without receiving local access parameters from the network at the time of transmission.
 21. A jamming-resistant system as defined in claim 19, comprising a detector of a security-breach event, wherein the transmitter is responsive to said detection of the security-breach event for transmitting the security data from the first station to the second station through the plurality of common access channels.
 22. A jamming-resistant system as defined in claim 19, comprising a detector of the presence of a jammer proximate the first station, said jammer producing an emission interfering with transmission from the network to prevent said transmission from the network to reach the first station, wherein the transmitter is responsive to detection of the presence of a jammer for transmitting the security data from the first station to the second station through the plurality of common access channels.
 23. A jamming-resistant system as defined in claim 19, wherein the transmitter comprises means for sending from the first station an autonomous registration frame to the plurality of common access channels of the wireless telecommunication network.
 24. A jamming-resistant system as defined in claim 21, wherein the wireless telecommunication network is an AMPS network, and wherein the jamming-resistant system further comprises: prior to detection of a security-breach event: means for receiving AMPS parameters from the network; means for updating the received AMPS parameters; and a memory for storing the updated AMPS parameters; and after detection of a security-breach event: a memory for storing the last updated AMPS parameters; and means for sending an autonomous registration frame to the network through the plurality of common access channels of the network selected in relation to the last updated AMPS parameters.
 25. A jamming-resistant system as defined in claim 24, further comprising: a processor for determining, in relation to the last updated AMPS parameters, a first common access channel and a last common access channel defining a range of access channels including said plurality of common access channels.
 26. A jamming-resistant system as defined in claim 23, wherein the transmitter comprises means for inserting the security data in the autonomous registration frame and transmitting said autonomous registration frame to the second station through the wireless telecommunication network.
 27. A jamming-resistant system as defined in claim 23, wherein the autonomous registration frame comprises a mobile identification number, and the transmitter comprises means for transmitting successive sets of security data respectively inserted in successive autonomous registration frames through the plurality of common access channels using a rotation of a plurality of mobile identification numbers in the successive autonomous registration frames.
 28. A jamming-resistant system as defined in claim 19, wherein the transmitter comprises means for transmitting said security data through the plurality of common access channels using respective access channel carriers.
 29. A jamming-resistant method as defined in claim 23, wherein the transmitter comprises: means for assigning at least one slave mobile identification number to the first station; means for encoding information by means of said at least one slave mobile identification number; and means for inserting said at least one encoded, slave mobile identification number in the autonomous registration frame.
 30. A jamming-resistant system as defined in claim 26, comprising: means for inserting in the autonomous registration frame a station identification number corresponding to the second station, and means for transmitting the autonomous registration frame to the second station through the wireless telecommunication network in response to the station identification number.
 31. A jamming-resistant system as defined in claim 30, wherein the autonomous registration frame is transmitted to the second station through a Cellemetry virtual network.
 32. A jamming-resistant system as defined in claim 19, wherein the transmitter comprises means for sending from the first station a random access channel sequence to the wireless telecommunication network.
 33. A jamming-resistant system as defined in claim 32, wherein the network uses a plurality of fundamental frequency carriers each having first and second time slots, and wherein the random access channel sequence is sent through the first time slot of the fundamental frequency carriers.
 34. A jamming-resistant system as defined in claim 33, further comprising means for inserting in the random access channel sequence a random number identifying the first station.
 35. A jamming-resistant method as defined in claim 33, further comprising: means for liberating the second time slot of the fundamental frequency carriers in response to reception of the random access channel sequence; and means for transmitting from the first station to the second station a second sequence including the security data through the second time slot of the fundamental frequency carriers.
 36. A jamming-resistant system as defined in claim 35, further comprising means for inserting in the second sequence a random number identifying the first station. 